Imagine signing a definitive purchase agreement for $20 million, popping the champagne at closing, and then discovering ninety days later that you owe the buyer back $800,000 — not because the business underperformed, but because a single line item in the contract called the "working capital peg" was set higher than what you actually delivered. This scenario plays out in mid-market M&A more often than sellers realize, and the painful part is that almost every dollar of that adjustment is preventable with better preparation, better numbers, and a sharper eye during the term sheet stage.
The net working capital peg is the most misunderstood mechanic in a business sale. Buyers love it because it protects them from a seller draining the company before closing. Sellers tolerate it because their advisors say it is "market standard." Yet very few owners stop to ask what the peg actually represents, how it is calculated, and how the post-closing true-up turns into a transfer of cash long after the seller has lost any leverage. This guide walks through every step of the peg from term sheet to final settlement and shows owners how to keep the working capital adjustment from quietly eating into the sale price.
What Net Working Capital Actually Is in a Deal
Net working capital, or NWC, is the operating liquidity a business needs to run day-to-day. The classic accounting formula is current assets minus current liabilities, but in an M&A context the definition is narrower. Cash is excluded because most deals are negotiated on a cash-free, debt-free basis — the seller keeps the cash and pays off the debt at closing. Interest-bearing debt, deferred tax balances, related-party balances, and certain accrued items are also typically stripped out. What remains is the working capital that funds the operating cycle:
- Trade accounts receivable
- Inventory
- Prepaid expenses tied to operations
- Accounts payable
- Accrued operating liabilities such as wages, vacation, sales tax, and customer deposits
The idea is straightforward. The buyer is acquiring an operating business and needs enough day-one liquidity to collect receivables, pay suppliers, replenish inventory, and meet payroll without immediately wiring in fresh capital. The peg is the dollar amount of that operating liquidity the parties agree the seller must leave behind at closing.
Why the Peg Exists at All
Before there was such a thing as a working capital peg, buyers had to either trust the seller not to game the working capital balance in the weeks before closing or pad the price for the risk that they would. Neither option worked well. A motivated seller could pull every lever to inflate cash and shrink working capital — accelerate collections by offering discounts, delay vendor payments past their due date, halt inventory purchases, and stretch payroll cycles. By the time the buyer took the keys, the operating cycle was a wreck and would need cash injections in week two.
The peg solves this by locking in a "normal" working capital level long before closing and then comparing it to what is actually delivered. If the seller delivers less working capital than the peg, the purchase price is reduced dollar-for-dollar by the shortfall. If the seller delivers more, the price increases by the surplus. The mechanic is technically value-neutral, but in practice it is the buyer's insurance policy against last-minute earnings management.
How the Peg Gets Set
Setting the peg is where most owners lose money, often without ever realizing it. The process usually plays out during financial due diligence, after the letter of intent is signed but before the definitive agreement is executed. Three choices determine the number.
The lookback window. Buyers typically average monthly working capital over a 12 to 24 month period to smooth out seasonality. A twelve-month average aligns nicely with trailing-twelve-month EBITDA, which is usually the basis for the enterprise value. A twenty-four-month average can mute recent improvements the seller has made. If your business has been getting more capital efficient — collecting faster, turning inventory better, stretching payables — a longer lookback drags the peg upward by including stale, less efficient months.
The normalization adjustments. Raw monthly NWC is rarely the right answer. Both sides will argue to strip out one-time events: a customer deposit on a project that has since closed, a large bad-debt write-off, an inventory build for a launch that did not repeat. Buyers tend to remove items that pushed working capital down (e.g., a one-time AP run before year-end), keeping the average higher. Sellers tend to remove items that pushed working capital up (e.g., an unusual inventory buildup), pulling the average lower. Every line item matters because the peg moves dollar-for-dollar with the final purchase price.
The definition itself. What counts as working capital? Some items are obvious — trade AR, inventory, trade AP. Others are gray zones that lawyers and accountants fight over: deferred revenue, customer deposits, accrued bonuses, sales tax payable, gift card liabilities, returns reserves, warranty accruals, and any prepaid that could be argued to be financing. The definitions in the purchase agreement should mirror the historical calculation method used to set the peg. Mismatched definitions are how sellers end up owing money they never planned to repay.
The "Free Working Capital" Trap
Here is the part that catches sellers off guard. If the buyer succeeds in setting a high peg, every dollar of working capital you must deliver beyond what your business naturally generates is, in effect, free working capital handed to the buyer. The enterprise value did not move, but you are now obligated to leave more cash and receivables behind than your operating model truly requires.
A seller who built a lean operation, invested in faster collections, and trimmed inventory by sourcing just-in-time will see the peg punish them for that discipline if the lookback is too long or the normalizations favor the buyer. A seller who has been running with high payables because of an extended vendor program will be told those balances should be normalized down because "buyers cannot count on terms continuing." Each adjustment quietly transfers economic value from seller to buyer without changing the headline price.
The defensive moves a seller can make before the peg is locked in include preparing a clean monthly NWC schedule going back at least 24 months, identifying every one-time event in advance with documentation, modeling what the peg looks like under several lookback windows, and pushing back on normalizations that are not symmetric. If the buyer wants to strip out a one-time event that lowered NWC, the seller should insist on stripping out the corresponding events that raised it.
Closing Day Mechanics
At closing, the seller does not know exactly what NWC will be — the books are not closed yet — so the parties exchange an estimated closing balance sheet a few days before the wire transfer. The seller's CFO or external accountant builds the estimate using the same definitions as the peg. If estimated closing NWC exceeds the peg, the wire to the seller is grossed up by the excess. If estimated closing NWC is below the peg, the wire is reduced by the shortfall. This is the first of two bites at the apple. The second comes 60 to 120 days later in the post-closing true-up.
Sellers should never rubber-stamp the estimated closing balance sheet. Every dollar that the buyer can chip off the estimate is a dollar that has to be clawed back through dispute resolution rather than collected from a cash wire. The estimate should reflect the seller's best, defensible view — not a conservative number designed to "leave room" for true-up movement. Buyers know that conservative sellers are easier to true-up against.
The Post-Closing True-Up
Sixty to one hundred and twenty days after closing, the buyer prepares the final closing balance sheet using the actual books. This is the true-up. The buyer compares the final NWC to the peg and computes a final adjustment. If the final NWC ended up higher than the estimate, the buyer pays more to the seller. If lower, the seller refunds the difference.
Two structural realities make the true-up dangerous for sellers. First, the buyer controls the books after closing, so the buyer is the one writing the final NWC calculation. Even a buyer acting in good faith has every incentive to be conservative — write down stale receivables more aggressively, reserve for slow inventory, accrue for the buyer's projection of returns. Second, the seller has already given up the company and lost negotiating leverage. Every dispute now happens through a contractual mechanism the seller agreed to, often with strict deadlines.
The standard process gives the seller a window — usually 30 to 45 days — to object to the buyer's true-up calculation. The objection has to be specific: which line items, what amounts, what the seller's proposed value is. After the objection, the parties negotiate for a defined period, typically 30 days. Anything still unresolved goes to an independent accountant who acts as an expert, not an arbitrator. The accountant rules on each disputed item but only within the range of the parties' proposed values. Fees are usually split in proportion to which party prevailed on each item.
Collars, Baskets, and Caps
To avoid disputes over trivial amounts, many SPAs include a "collar" — a tolerance band around the peg where no adjustment payment is made. There are two common collar structures. A tipping basket says no payment until the deviation exceeds the band, but once the band is broken the full deviation pays from dollar one. A deductible says no payment up to the band, and only the portion above the band pays. The difference is meaningful: if the band is $200,000 and the actual deviation is $250,000, a tipping basket pays the full $250,000 while a deductible pays only $50,000.
Some agreements also cap the size of the working capital adjustment, often at a percentage of purchase price. Caps protect both sides from extreme outcomes but tend to favor sellers because the typical risk is a buyer claiming a large downward adjustment.
Common Mistakes That Cost Sellers Money
A few patterns show up over and over in deals that end badly for the seller.
Letting the buyer's quality of earnings team set the peg unchallenged. The buyer's financial advisors will build the peg from their model. If the seller does not bring an independent calculation to the table, the buyer's number becomes the default.
Inconsistent definitions between the peg and the SPA. The agreement should reference the exact schedule used to build the peg, with the same accounts included and the same accounting principles applied. Inconsistencies almost always favor the side that wrote the schedule.
Ignoring seasonality in the closing date. Closing in a working-capital-heavy month and being measured against an annual average pegs the seller for failure. Sophisticated agreements either time the closing for a neutral month or use a seasonally adjusted peg.
Underestimating deferred revenue, customer deposits, and gift card liabilities. These are usually classified as working capital liabilities and reduce NWC. A seller who has been collecting upfront from customers and recognizing revenue over time has likely been building a meaningful deferred revenue balance that will hit the closing balance sheet hard.
No documentation for normalization adjustments. Every one-time item the seller wants stripped out needs contemporaneous documentation. Verbal explanations during true-up disputes carry almost no weight.
Failure to monitor working capital between signing and closing. The peg is locked in at signing, but actual NWC keeps moving until closing. Sellers who do not track it weekly often hand the buyer a windfall — or trigger an unwelcome shortfall — without realizing it.
A Seller's Checklist Before the Term Sheet Is Signed
Owners who plan to sell should start preparing the working capital narrative long before the letter of intent arrives. Practical steps that pay off:
- Build a clean, accrual-basis monthly balance sheet going back at least twenty-four months.
- Map every current asset and current liability into "NWC" or "non-NWC" buckets consistent with how the eventual deal will define them.
- Identify and document every one-time event that pushed NWC above or below normal — pricing inflation, supplier disruptions, customer deposit spikes, large bad-debt write-offs.
- Calculate a 12-month rolling NWC average and a 24-month rolling average. Note the difference and understand why.
- Test the peg against the most likely closing month. If the close is in a seasonally heavy month, the actual delivered NWC will be different from the average.
- Make sure your bookkeeping is current and your accruals are not deferred to year-end. Sloppy monthly books make peg negotiations brutal because the buyer's QoE team will normalize everything in the buyer's favor.
Where Bookkeeping Quality Becomes Money
The single highest-leverage factor in a working capital negotiation is the cleanliness of the seller's monthly accrual-basis financials. A seller who only closes the books once a year — or who uses cash-basis accounting throughout the year and rolls it up to accrual at year-end — is starting the peg negotiation from a position of weakness. The buyer will simply use its own quality of earnings work to estimate every monthly NWC balance, and any seller pushback will sound like an argument against the buyer's numbers rather than a counter-proposal grounded in the seller's own records.
Owners who maintain monthly close discipline — reconciling AR aging, counting inventory regularly, accruing wages, sales tax, and vacation on schedule, and recognizing deferred revenue consistently — bring a credible NWC schedule into the room. That schedule does not have to be perfect, but it has to exist, and it has to match how the business actually operates. Buyers respect numbers they cannot rebuild from scratch in two weeks of due diligence. Sellers with two-plus years of clean monthly books typically negotiate pegs that are 5 to 15 percent more favorable than sellers who show up with a year-end-only close.
Keep Your Books Sale-Ready Long Before the Term Sheet
When the buyer's advisors start dissecting your monthly working capital trends, the quality of your accounting records becomes a direct lever on your sale price. Beancount.io gives owners a plain-text, version-controlled, auditable financial system that produces consistent monthly accrual-basis balance sheets without locking your data inside a proprietary platform — exactly the kind of bookkeeping discipline that turns a peg negotiation in your favor. Get started for free and build the financial record that buyers cannot poke holes in.